Weight controlled self lift elevator



Sept. 29, 1959 c. P. BRUMBY 2,906,374

WEIGHT CONTROLLED SELF LIFT ELEVATOR I Filed Sept. 50, 1957 INVENTORI 6R .ERUMBY, BY

19 T70 RNE X United States Patent WEIGHT CONTROLLED SELF LIFT ELEVATORClarence P. Brumby, Glendale, Calif. Application September 30, 1957,Serial No. 687,253

:1 Claim. (Cl. 18717) This invention relates to elevators for buildingsand has particular reference to an automatically functioning elevator.

Most elevators used at the present time are electrically orhydraulically operated and while such power operation may be necessaryin ordinary installations, there are times when an automaticallyoperated elevator is sorely needed. In warehouses, for example, whererefilling of the storage space from time to time is performed by suchconventional elevators, it may be found most con' venient and economicalto perform the many minor daily dispensing operations by means of adevice requiring no such power operation.

In homes and in apartment buildings where stairways constitute the solemeans of exit it is in cases of emergencies, such as fires, often foundthat casualties occur because such stairways are inadequate to providemeans for safe escape, particularly where infants, elderly people andphysically handicapped persons seek escape.

It is in view of the foregoing the object of the present invention toprovide escape means which is at all times ready for service and whichwill perform its service automatically, thereby entirely eliminating thepower devices of conventional elevators.

These and other objects of the invention will be ap parent from thefollowing detailed description and by referring to the accompanyingdrawings in which preferred forms of the invention are illustrated.

In the drawings:

Fig. 1 is a schematic elevational view of a device embodying theinvention;

Fig. 2 is a similar view showing the device in a different position ofadjustment;

Fig. 3 shows a somewhat modified form of the invention; and

Figs. 4 and 5 illustrate parts of this modified structure.

The device of the invention includes a pulley 1 which is mounted forrotation in a suitable bracket 2 which is held suspended from a beam orceiling 3 of a building. A cable 4 of any required length is placed onthe pulley to support the elevator cage A.

At the base of the building is placed a cylinder in axial alinement withthe free end of the cable 4 and a piston 11 is seated for verticalsliding movement in this cylinder. A piston rod 12 extends from thepiston through a cap 13 at the upper end of the cylinder to the free endof the cable 4. A counterweight 14 is in any suitable manner fastened tothe adjoining ends of the rod and cable. It is important to note thatthis counterweight is so much heavier than the empty cage it normallywill maintain the cage in the elevated position indicated in Fig. 1 ofthe drawings.

A tank 20 is placed near the upper end of the cylinder to which it isconnected by means of conduit 21 and a tubular channel 22 extends fromthe tank to the lower end of the cylinder. A suitable fluid poured intothe tank completely to fill the cylinder and the conduits there- ICC thetank opening.

When a load is placed in the cage or a passenger enters the cage, and ifthe load is heavy enough to over-balance the counterweight, it is foundthat the cage will descend, in descending to cause the piston 11 to risewithin the cylinder and in rising to cause the fluid to circulatethrough the conduits and the tank. Once the cage again has beenevacuated, it is found that the counterweight is capable of returningthe cage to its normal, elevated position.

Means must be provided for controlling the speed of descent and sincethe device, as above pointed out, may be installed in placm none ofwhich require the same load capacity, it is important to provideadditional speed control in each installation. This may be done byplacing in the conduit 21 an element 24 having a passage therethrough ofthe required diameter in each case.

As above pointed out, it is one of the main objects of the invention toprovide a device for use as a fire escape. In such cases it is importantto provide means for controlling the speed of the starting and stoppingmovements of the cage to the end that these movements may be effectedsmoothly, without danger of sudden starting jerks and stopping bumpsdiscomforting the occupant or damaging the load in the cage.

The lower end of the conduit 22 is for this purpose shown divided intotwo horizontally directed branches 26, 27 the distance between which isabout equal to the height of the piston 11. The lower branch is smallerin diameter than the upper branch. At the start of the downward cagemovement it is found that the fluid only can reach below the pistonthrough the smaller lower branch thereby to counteract a sudden startingmovement. Full speed of the cage descending movement is not attaineduntil the piston rises above the upper branch 26.

It is now noticed that a second conduit 28 is in Fig. 3 placed a shortdistance below the upper conduit 21. The fluid is free to pass throughboth of these conduits until the piston reaches and gradually closesthis second conduit gently to slow down the cage movement to bring thecage to a gentle stop. This combination assures safe and comfortabledescent of the person or persons occupying the cage even in the case ofphysically handicapped occupants. An element 29, similar to the element24, should be placed in this second conduit to assure properslowing-down speed.

Once the occupant has left the cage, it is found that the counterweightwill return to its elevated position. In cases where the device servesas a fire escape, it is essential to expedite the return movement of thecage for use by other persons endeavoring to escape from the fire. Thismay be done in the manner best shown in Figs. 4 and 5 of the drawings.

The piston is for this purpose made thimble-shaped and the rod 4 is inany suitable manner, as by a pin 31, rigidly mounted in the top plate 30of the piston. In addition, it is important to note that a number ofpassages 32 extend through this top plate. A cover 33 is mounted abovethe piston for sliding movement on the piston rod 4. This cover willduring the upward movement of the piston by fluid pressure within thecylinder above the piston be held tightly against the upper platethereof to maintain these passages closed and so to insure safedescending movement of the passenger supporting cage. But the moment thecage is evacuated and the heft of the counterweight commences to lowerthe piston it is found that the cover 33, by the fluid pressure withinthe lower portion of the cylinder is held against downward movement withthe piston. The fluid is now free to escape through the passages 32 andrapid, unrestricted return' movement of the cage to its upper positionis assured.

It was above stated that the cable may be of any required length and anadditional pulley may be placed above the counterweight, as shown inFig. 3, to provide room for such longer cable within a limited space.

This application is a continuation in part of my co-' pendingapplication, Ser. No. 422,905, filed April 13, 1954, which hereby isabandoned.

I claim:

A self-lift elevator comprising, a cage, a pulley mounted for rotationin a stationary bracket, a cable extending from the cage over the pulleyand vertically downward therefrom, 'a stationary cylinder below thepulley in axial alinement with the dependent end of the cable, a pistonin the cylinder, a rod extending from the piston to the cable, a tank, aconduitfromthe tank-tothe upper end of the cylinder, a similar secondconduit a distance below the first conduit substantially equal to theheight of the piston, flow controlling elements in the two conduits, twoconduits from the tank to the lower end of the cylinder, one above theother a distance substantially equal to the height of the piston, thelower conduit being smaller in diameter than the conduit directly aboveit.

References Cited in the file of this patent UNITED STATES PATENTS407,677 Nickerson July 23, 1889 548,978 Foster Oct. 29, 1895 1,078,060Newman Nov. 11, 1913 1,136,140 Jansson Apr. 20, 1915 1,820,427 BirmannAug. 25, 1931 2,417,947 Reedy Mar. 25, 1947 FOREIGN PATENTS 30,032 GreatBritain Apr. 21, 1910

